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Desertification
Desertification is a type of gradual land degradation of Soil fertility, fertile land into arid desert due to a combination of natural processes and human activities. The immediate cause of desertification is the loss of most vegetation. This is driven by a number of factors, alone or in combination, such as drought, climatic shifts, tillage for agriculture, overgrazing and deforestation for fuel or construction materials. Though vegetation plays a major role in determining the Soil biology, biological composition of the soil, studies have shown that, in many environments, the rate of erosion and runoff decreases exponentially with increased vegetation cover. Unprotected, dry soil surfaces blow away with the wind or are washed away by flash floods, leaving infertile lower soil layers that bake in the sun and become an unproductive hardpan. At least 90% of the inhabitants of drylands live in Developing country, developing countries, where they also suffer from poor economic and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Nations Convention To Combat Desertification
The United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa (UNCCD) is a Convention to combat desertification and mitigate the effects of drought through national action programs that incorporate long-term strategies supported by international cooperation and partnership arrangements. The Convention, the only convention stemming from a direct recommendation of the Rio Conference's Agenda 21, was adopted in Paris, France, on 17 June 1994 and entered into force in December 1996. It is the only internationally legally binding framework set up to address the problem of desertification. The Convention is based on the principles of participation, partnership and decentralization—the backbone of good governance and sustainable development. It has 197 parties, making it near universal in reach. To help publicise the Convention, 2006 was declared " International Year of Deserts and Desertifica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sahel Drought
The Sahel region of Africa has long experienced a series of historic droughts, dating back to at least the 17th century. The Sahel region is a climate zone sandwiched between the Sudanian Savanna to the south and the Sahara desert to the north, across West and Central Africa. While the frequency of drought in the region is thought to have increased from the end of the 19th century, three long droughts have had dramatic environmental and societal effects upon the Sahel nations. Famine followed severe droughts in the 1910s, the 1940s, and the 1960s, 1970s and 1980s, although a partial recovery occurred from 1975-80. The most recent drought occurred in 2012. While at least one particularly severe drought has been confirmed each century since the 17th century, the frequency and severity of recent Sahelian droughts stands out. Famine and dislocation on a massive scale—from 1968 to 1974 and again in the early and mid-1980s—was blamed on two spikes in the severity of the 1960-1980 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desert
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or Semi-arid climate, semi-arid. This includes much of the Polar regions of Earth, polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night strain the Rock (geology), rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting frag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reclaiming Desert
Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life. The term "desert greening" is intended to apply to both cold and hot arid and semi-arid deserts . It does not apply to ice capped or permafrost regions. It pertains to roughly 32 million square kilometres of land. Deserts span all seven continents of the Earth and make up nearly a fifth of the Earth's landmass, areas that recently have been increasing in size. As some of the deserts expand and global temperatures increase, the different methods of desert greening may provide a possible response. Planting suitable flora in deserts has a range of environmental benefits from carbon sequestration to providing habitat for desert fauna to generating employment opportunities to creation of habitable areas for local communities. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Degradation
Land degradation is a process where land becomes less healthy and productive due to a combination of Human impact on the environment, human activities or natural conditions. The causes for land degradation are numerous and complex. Human activities are often the main cause, such as unsustainable land management practices. Natural hazards are excluded as a cause; however human activities can indirectly affect phenomena such as floods and wildfires. One of the impacts of land degradation is that it can diminish the natural capacity of the land to store and filter water leading to water scarcity. Human-induced land degradation and water scarcity are increasing the levels of risk for agricultural production and ecosystem services. The United Nations estimate that about 30% of land is degraded worldwide, and about 3.2 billion people reside in these degrading areas, giving a high rate of environmental pollution. Land degradation reduces agricultural productivity, leads to biodiversity l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drylands
Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65."Millennium Ecosystem Assessment, 2005. Drylands Systems". Chapter 22 in: ''Ecosystems and Human Wellbeing: Current State and Trends'', Volume 1. Island Press. Drylands can be classified into four sub-types: * Dry sub-humid lands * Semi-arid lands * Arid lands * Hyper-arid lands Some authorities regard hyper-arid lands as deserts (United Nations Convention to Combat Desertification) although a number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands. Drylands cover 41.3% of the Earth's land surface, including 15% of Latin America, 66% of Africa, 40% of Asia, and 24% of Europe. There is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sahel
The Sahel region (; ), or Sahelian acacia savanna, is a Biogeography, biogeographical region in Africa. It is the Ecotone, transition zone between the more humid Sudanian savannas to its south and the drier Sahara to the north. The Sahel has a Semi-arid climate#Hot semi-arid climates, hot semi-arid climate and stretches across the tropics, southernmost latitudes of North Africa between the Atlantic Ocean and the Red Sea. Although geographically located in the tropics, the Sahel does not have a tropical climate. Especially in the western Sahel, there are droughts in the Sahel, frequent shortages of food and water due to its very high Corruption Perceptions Index, government corruption and the semi-arid climate. This is exacerbated by very high list of countries by birth rate, birthrates across the region, resulting in a rapid increase in population. In recent times, various Coup Belt, coups, Foreign internal defense#Preemptive counterinsurgency in Africa, insurgencies, terrorism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aridity
Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata-Rocha, W., Monjardin-Armenta, S. A., Franco-Ochoa, C., & Zambrano-Medina, Y. G. (2021). The Identification and Classification of Arid Zones through Multicriteria Evaluation and Geographic Information Systems—Case Study: Arid Regions of Northwest Mexico. ''ISPRS International Journal of Geo-Information'', ''10''(11), 720. https://doi.org/10.3390/ijgi10110720 These areas tend to fall upon degraded soils, and their health and functioning are key necessities of regulating ecosystems’ atmospheric components. Change over time The distribution of aridity at any time is largely the result of the general circulation of the atmosphere. The latter does change significantly over time through climate change Present-day climate chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drought
A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021Water Cycle Changes. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010. A drought can last for days, months or years. Drought often has large impacts on the ecosystems and agriculture of affected regions, and causes harm to the local economy. Annua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Similarly, household food security is considered to exist when all the members of a family have consistent access to enough food for an active, healthy life. Food-secure individuals do not live in hunger or fear of starvation. Food security includes resilience to future disruptions of food supply. Such a disruption could occur due to various risk factors such as droughts and floods, shipping disruptions, fuel shortages, economic instability, and wars. Food insecurity is the opposite of food security: a state where there is only limited or uncertain availability of suitable food. The concept of food security has evolved over time. The four pillars of food security include availability, access, utilization, and stability. In addition, there are tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobi Desert
The Gobi Desert (, , ; ) is a large, cold desert and grassland region in North China and southern Mongolia. It is the sixth-largest desert in the world. The name of the desert comes from the Mongolian word ''gobi'', used to refer to all of the waterless regions in the Mongolian Plateau; in Chinese, ''gobi'' is used to refer to rocky, semi-deserts such as the Gobi itself rather than sandy deserts. Geography The Gobi measures from southwest to northeast and from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°–89° east). Its area is approximately . Gobi includes the long stretch of desert extending from the foot of the Pamirs (77° east) to the Greater Khingan Mountains, 116–118° east, on the border of Manchuria; and from the foothills of the Altay, Sayan, and Yablonoi mountain ranges on the north to the Kunlun, Altyn-Tagh, and Qilian mountain ranges, which form the northern edges of the Tibetan Pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals. Overgrazing reduces the usefulness, productivity and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds. Degrading land, emissions from animal agriculture and reducing the biomass in a ecosystem contribute directly to climate change between grazing events. Successful planned grazing strategies have been in support of the American bison of the Great Plains, or migratory wildebeest of the African savannas, or by holistic planned grazing. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
